I did a system in a buddys 209 a few years back. The section @ the drivers feet has a huge foot rest. If you wanna leave it there then I have no suguestions for you but if you feel like chopping it out its no big deal here are some pictures

we had a ten in a ported box in our x-9. It fit fine and you still had plenty of leg room... the sub was facing out towards the water. ill try to get a pic posted. It was a mtx 7500 ten. it hit very well for one ten